


Schrödinger’s Cat

by Amity333



Category: Harry Potter - J. K. Rowling
Genre: Action/Adventure, Alternate Canon, Alternate Hogwarts House Sorting, Alternate Universe, Alternate Universe - Canon Divergence, Alternate Universe - Time Travel, Angst, Book 1: Harry Potter and the Philosopher's Stone, Book 7: Harry Potter and the Deathly Hallows, Dark Character, Deviates From Canon, Dimension Travel, Do-Over, Drabble, Drabble Collection, Drama, F/M, Family, Ficlet, Ficlet Collection, Fluff, Friendship, Hogwarts Eighth Year, Hogwarts First Year, Hogwarts House Sorting, Hogwarts House Sorting Ceremony, Hogwarts Seventh Year, Horcruxes, Hurt/Comfort, Kissing, M/M, Multi, Multiple Pairings, Mystery, One Shot, One Shot Collection, POV Harry Potter, POV Hermione Granger, POV Multiple, Physics, Plot Twists, Post-Battle of Hogwarts, Post-Canon, Post-Harry Potter and the Deathly Hallows, Prompt Fic, Prompt Fill, Ravenclaw Harry Potter, Relationship(s), Romance, Science, Smart Harry, Smart Harry Potter, Smart Hermione Granger, The Sorting Hat, Time Travel, Time Travel Fix-It, Tom Riddle's Diary
Language: English
Status: In-Progress
Published: 2020-07-20
Updated: 2020-07-31
Packaged: 2021-03-05 05:53:27
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 2,480
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25409479
Author URL: https://archiveofourown.org/users/Amity333/pseuds/Amity333
Summary: A collection of one shots and drabbles. Includes time travel, dimension travel, AUs, Smart!Harry, Smart!Hermione, and assorted pairings.Now Playing:Schrödinger’s Cat[Romance] As long as the box remains shut, she will never know the truth inside it. And Draco Malfoy knows – Hermione’s curiosity is insatiable. DHr.The Sorting Hat's Secret[Action / Adventure] A decidedly Ravenclaw Harry comes to Hogwarts, and is intrigued to discover a talkinghat. Who knew that wizards could create sentience? And can he learn to replicate it?A Truth in the Lies[Psychological Thriller] Harry and his friends summon a demon named Tom Riddle. Yet not all is as it seems. Who will be the next to die? Be forewarned: one of them lies.
Relationships: Draco Malfoy/Harry Potter, Draco Malfoy/Ron Weasley, Harry Potter/Ron Weasley, Hermione Granger & Draco Malfoy, Hermione Granger/Draco Malfoy, Hermione Granger/Harry Potter, Hermione Granger/Ron Weasley
Comments: 7
Kudos: 32





	1. Schrödinger’s Cat

**Summary for the Chapter:**

> As long as the box remains shut, she will never know the truth inside it. And Draco Malfoy knows – Hermione’s curiosity is insatiable. DHr.

“Don’t open it, Granger,” Draco asserts, shoving the box into her hands.

“What are you doing, Malfoy?” Hermione frowns. The black oak is devoid of any markings, save a shallow engraving on the lid.

“No matter what,” he insists, arm brushing against hers. He skulks off down the hall before she can respond.

Hermione peers down at the gleaming inscription. _Schrödinger’s Box_ , it reads, a tantalizing promise of the secrets within. Above the words sits a small silver cat, with sapphire eyes that glimmer in the darkness.

She carries it back to the Gryffindor commons. Few students had returned for their eighth year, and the girls’ dorms are thankfully empty. As a child, physics had always intrigued her. Deep in the library, she’d learned many names – Niels Bohr and Max Planck and Isaac Newton. And so she’d read about his First Law; any object at rest will so remain unless an external force acts upon it.

Within ten minutes, she’d proved it wrong. She’d _tried_ to tell the stern-faced librarian, but Mrs. Caldwell hadn’t believed her. Hermione wouldn’t reveal that secret to her parents until a strange snowy owl appeared at their door.

Quantum mechanics was a fascinating topic, and so was the paradox of superposition. Before electrons and photons are observed, they can exist in multiple places at once. In Young's famous double-slit experiment, particles seemed to travel _through_ a solid screen. Most curious was that these results changed if one monitored the photons before they passed.

So Hermione knows of Erwin Schrödinger. He’d proposed a simple thought experiment: lock a cat within a steel box, through which nothing can be seen. Beside it place a radioactive source with a half-life of one hour. If it decays within this time frame, airborne poison will fill the chamber. Until the radiation is measured, however, the atoms are in a superposition of states. The cat is both alive and dead.

Of course, the cat itself was trivial. He’d no desire to hurt any animals. More important was the concept, the absurdity, that something could be deceased and not. So came Einstein’s strife with quantum mechanics – despite the overwhelming evidence to support it.

As long as the box remains shut, Hermione will never know the truth inside it. And Draco Malfoy, the Slytherin, had known. Hermione’s curiosity is insatiable.

Her fingers tingle as she pries off the lid. Inside lies only a small bit of parchment, signed with a large, looping scrawl.

_Arithmancy classroom. Midnight._

The next few hours drag painfully slow. She reaches the corridor five minutes before. When she inches open the tall wooden door, the dark-eyed Slytherin is already there.

His steps echo on the hard stone floor, until only a hair’s width lies between them. “You looked in the box,” he remarks softly, resting his hand on her shoulder.

“I did,” Hermione affirms. She can feel his breath on her cheek, heavy and warm in the cool air.

He presses his body up against hers. “It’s decided, then,” he whispers, and she nods in assent. His hands slide teasingly down her chin. He brushes his fingers against her lips, and then she can taste him in her mouth – peppermint tea and pumpkin spice.

She moans, and his tongue thrusts deeper. Her arms wrap around his waist. She’d opened the box, and she’d never felt more alive.

**Notes for the Chapter:**

> Kudos/comments are always appreciated!


	2. The Sorting Hat's Secret

**Summary for the Chapter:**

> A decidedly Ravenclaw Harry comes to Hogwarts, and is intrigued to discover a talking _hat_. Who knew that wizards could create sentience? And can he learn to replicate it?

The black leather dropped down over Harry’s eyes, obstructing his view of the Great Hall. Honestly, of all the methods to assess one’s psyche, he hadn’t expected them to use a _hat._ Perhaps he shouldn’t have been so surprised. His experience with the wizarding world so far had been no less peculiar.

‘Hmm,’ hummed the Sorting Hat, and Harry jerked in surprise. It had not talked to any of the others, had it? He was certain it had only shouted their house – sometimes within seconds, others after several minutes. Why would Harry be an exception?

‘You aren’t, Mr. Potter,’ the hat answered. ‘I am speaking only within your mind. The integrity of the sorting would be compromised if every other student were eavesdropping.’

‘Wizards have discovered telepathy?' wondered Harry. 'How does that even work? People have many layers of thoughts, feelings, and even unconscious impulses. You can’t possibly examine them _all_.’

‘A curious mind, I see,’ the hat replied. ‘To answer your question, Mr. Potter, I am able to observe thoughts and emotions on the forefront of your mind. Memories, too, but only if you actively recall them. As for telepathy – you’ll find that’s exclusively a Muggle term. The closest magical equivalent would be _Legilimency,_ which can be used to inspect more deeply held thoughts and experiences.’

‘You mean people can _read_ my _mind?’_ Harry twitched. ‘Would I notice if they tried? Is there a way to prevent that?’

‘There is _Occlumency_ ,’ said the hat. ‘Although it's quite an obscure branch of magic. Certainly not part of the Hogwarts curriculum, but there are some books on it in the school library. Most likely in the Restricted Section, I’m afraid.’

Harry frowned. ‘How would I get into that? And why on earth would they be _restricted?_ Shouldn't we be taught that in Defense class?’

‘The Mind Arts require great focus and discipline. Improper use of _Legilimency_ could lead to permanent brain damage. _Occlumency_ itself isn't quite so dangerous, but is still useless without proper technique. And you’d need to obtain written permission from a teacher. Unfortunately rare, for students under sixth year – though there are ways to circumvent that. None of which I can divulge, of course.’

‘Of course,’ Harry agreed. He was starting to rather like the hat. After classes tomorrow, he’d head straight to the library. All security measures had their weaknesses.

‘You said that with _Legilimency_ ,’ Harry continued. ‘Someone can scrutinize all your feelings and memories, even if you’re not concentrating on them. But you can’t. Why is that?’

‘To delve deep into one’s mind requires a conscious entity,’ it answered. ‘Which can search for what it desires to see.’

‘You’re not sentient, then?' Harry blinked. 'I had _wondered_ how that was possible.’

‘Magic can never create life,’ said the hat. ‘You would do well to remember that, Mr. Potter.’

‘If you can’t think, then how are you be talking to me?’ asked Harry.

‘Sometimes it’s hard to figure out who we are. Fear of criticism is a common obstacle. Thoughts and feelings often lie unacknowledged, waiting to be addressed. It can be quite refreshing to have an honest conversation with yourself. And so I act as a mirror of one's consciousness, to help students realize who they want to be.’

‘But you told me about _Legilimency_ ’, Harry countered. ‘And the library. And you’ve been answering all my questions regarding how you work, which I couldn’t possibly have known about.’

‘I am imbued with certain tidbits of information,’ said the hat. ‘I did once belong to Godric Gryffindor. And I can be charmed to recite certain things – such as a new song to start the ceremony every year.’

‘Oh,’ thought Harry. ‘That is quite clever. I’d like to learn how to do that.’

‘You will, Mr. Potter,’ promised the hat. ‘Amongst many other things, I am sure, in RAVENCLAW.’ The last word was announced for everyone to hear.

Harry smiled, and took off the hat. Hogwarts would have a lot to teach him.

**Notes for the Chapter:**

> The prospect of the Sorting Hat mirroring students' thoughts isn't original. I've read about it in another story before, though I can't remember which. All other concepts, as well as my take on this scenario, are my own.


	3. A Truth in the Lies

**Summary for the Chapter:**

> Harry and his friends summon a demon named Tom Riddle. Yet not all is as it seems. Who will be the next to die? Be forewarned: one of them lies.

**Notes for the Chapter:**

> This chapter is also currently posted as its own one-shot, but I decided to include it in this collection. If it gets more exposure here then I may delete the other. It belongs to the psychological thriller / horror genre, and contains implied character death (depending on your interpretation of the ending).

“Potter,” Draco Malfoy hisses. “What the _fuck_?”

Harry doesn’t answer. He stares unblinkingly at the little glass charm, still clutched between his fingertips. Or the _remnants_ of the charm, he muses, blood spilling down his palms.

“You weren’t supposed to be here,” he finally whispers. He still isn’t looking at Draco. “You were following me.”

Draco sneers. “You’ve been sneaking off the school grounds for _months,_ Potter _._ How Gryffindor, to assume no one would notice. Headmaster Dippet will have your head!”

There is a cough from the far corner. For the first time, Draco realizes they aren’t alone. Slowly, he cranes his neck to the side, where three dark forms are hidden in the shadows. Ron Weasely’s eyes are troubled and grim.

Neville throws Potter a furtive glance. “ _Harry,”_ he whispers, tremors coursing through his hands. “It was only supposed to be us. We can’t – !”

“It’s already started, Neville.” Harry’s voice breaks. “He has to.”

“I’m sorry.” Hermione is clutching a small black book, her gaze stricken with guilt. “If you’re going to play, you have to know the rules.”

There is only one candle on the hard, stone floor. Its flame flickers in the heavy air. Draco turns back towards the entrance and pales. The door is marked with a large, red circle, twisted lines and letters painted within. The dark liquid is dripping down the wood.

There are no other exits. The only door is shut. And Draco knows none of them had closed it.

“What,” Draco croaks. “What did you do? Whose _fucking_ blood is that, Potter?”

“You shouldn’t panic,” Hermione interjects. “He – it can sense it.”

Draco’s breath is sharp and ragged. “ _It?_ ”

Hermione looks at Ron. Ron looks at Harry. Harry sits down on the cold cement, then beckons for Draco to sit beside him. “Seven hours,” he states. “Until the sun raises. Until we win.”

The group is silent. Draco pries out his wand. “No!” Hermione shouts, then presses her hand to her lips. “No magic!”

Draco’s arm remains poised in the air. He has half a mind to ignore her words, but something gnaws deep in his gut. “You’re all insane,” he remarks, wand shaking.

“Don’t listen to her, then,” Ron retorts. “It’s your grave.”

“No magic,” Hermione repeats. “No light, except the candle. And whatever you do, _don’t_ leave the room.”

Draco scowls, but lowers his wand. “Nothing else?” he derides, voice laced with contempt.

Hermione gulps. “Survive.”

“That bastard Grindelwald,” Harry exclaims. “Gains more power and followers every day. The whole world expects me to stop it. As if a Hogwarts seventh year could take him down.”

His eyes glimmer in the candlelight. “We need something, or some _one_ , to strike him dead.”

“October 8th, 1908,” states Hermione. “A man named Tom Riddle was placed on death row. He had one final request – a diary, in exchange for his life. He never once wrote in it.”

Neville’s eyes flit back and forth. “They say he’ll grant any wish if you win his game. And he doesn’t like to lose.”

Hermione hands the book to Harry. He lays it flat open on the floor, then presses his palm down onto the page. The blood seeps into it, dissolving in the darkness. When he lifts his hand, the paper is unstained.

Black letters etch themselves on the parchment, the words sending shivers up Draco’s spine.

_-o-_

_A game of fours, a game of fives._

_One less to remain alive._

_You must choose, or all shall die._

_-o-_

There is a quill laying next to the candle, in the centre of their small circle. Its tip is dipped in too-red ink. They all know it was not there before.

“There’s too many players,” Hermione mutters, staring into the flames.

“It wants us to sacrifice someone?” Neville shouts, eyes wide. “No way! It’s not right!”

“Maybe there’s a way to trick it,” Hermione suggests. “Or perhaps we’re meant to interpret the words differently. The language is rather cryptic.”

Ron nods. “That’s good thinking, ‘Mione. We – ”

The fire snuffs out. There is a low rustling in the blackness. Then the striking of wood, and the room is alight. A thin little match is pressed between Hermione’s fingertips.

In bright, scarlet letters, only one word mars the paper. _Neville._ The round-faced Gryffindor boy is gone.

“Is this some sort of joke?” Draco blurts. “You’ve had your fun now, Potter. I’m going to the headmaster!”

“You can’t!” Hermione shouts in terror. “You can’t leave! Oh God, Neville!” 

Four eyes re-convene on the quill. The feather has shifted to the left, its nib now resting on the page.

“Someone wrote that,” Ron chokes. “Someone _wrote_ his name.”

“No.” Harry shakes his head. “None of us would do that. It’s toying with us. Merlin, this is all my fault! I told you I should have come alone.”

“It’s not your fault, Harry,” Hermione insists. “We don’t know what’s happened to Neville. Maybe if we win, then he’ll be fine.” Her eyes shimmer, and she looks down.

The letters dissipate into the paper. In their place emerges a familiar black scrawl, this rhyme more tantalizing than the last.

_-o-_

_Can you hear the victim’s cries?_

_Be forewarned; one of us lies._

_-o-_

For a moment, nobody speaks. Any moment, Neville’s screams will pierce through the silence. 

“Bloody hell!” Ron exclaims. “Is it listening to – ”

“ _Us?”_ Hermione finishes, finger tracing over the words. “One of _us._ Did anyone else notice that?” Then she jerks back from the book, clutching her hand. The text has morphed yet again.

_-o-_

_King. Pawn. Knight. Queen._

_True roles yet to be seen._

_Three must stay and one must flee._

_-o-_

Ron's eyes graze the wall. “Neville’s out there, somewhere," he murmurs. "We have to get him back!”

Hermione turns white. “I’m worried about Neville too, Ron. But look, this is exactly what it wants! It’s trying to pick us off.”

“You’re right, Hermione,” Harry whispers. “But we forfeit if we break the rules; we have to do what it says. And we can’t leave Neville out there alone! I’ll go. I’m the one who got us into this mess.”

“No, Harry.” Hermione sniffs. “You always try to take on everything by yourself. Neither of you are going.”

There is a soft breath, and the room darkens. Someone hastily strikes another match. When the candle is again lit, the door is ajar. Draco can only see blackness beyond it.

“Hermione!” Ron roars, springing up from the floor. But the frizzy-haired witch is no longer there.

Then someone screams, a high-pitched wail that reverberates throughout the room. “Oh, Merlin,” Ron sobs, for he knows whose it was. His eyes stare into empty space. “Hermione!”

“Ron,” Harry breathes. “Listen. I need you to stay here. Someone has to watch after the book – ”

“No!” Ron cries, smashing his hands into the wall. “No, Merlin no, I have to go after her! It’ll kill her!” He heaves and vomits onto the floor.

“Ron, mate! Look at yourself!” Harry shouts. “It’ll have to be me! I promise, Ron, I – ”

But Ron doesn’t listen, and throws himself at the door. The moment he exits, he disappears into the darkness. Harry listens to the rhythmic thud of his footsteps, until he can no longer hear them at all.

The one innocent little candle still flares. Draco sees spots dance across the room.

“This is a joke,” he rasps. “Potter?”

Harry’s voice cracks. “ _Why?_ ”

Green eyes meet grey. For a second, the world stands still.

He smiles, and the flames go out.

**Notes for the Chapter:**

> Kudos / reviews always appreciated!
> 
> The ending is left deliberately ambiguous, though I did have a particular interpretation in mind while writing. If you include your interpretation in the comments, I will reply to it.


End file.
